This project aims to combine assessment of hearing abilities among subjects of different ages over time, together with information from their communication and health histories. Medical and cognitive data collected from subjects in the longitudinal study will be examined with respect to the audiologic and case history data. Specifically, the objectives of this project are: A) To study the contribution of medical, genetic, dietary and social factors to age-related auditory dysfunction; B) To determine to what extent age, independent of other etiologic factors, causes a deterioration in hearing abilities; C) To identify specific hearing abilities and auditory system functions that exhibit the greatest age-related decrements, and to determine whether these changes are associated with other age-related changes in the individual; D) To study the influence of age-related changes in cognition to decrements in speech understanding ability; and E) To examine age-associated changes in self-perceived hearing handicap in relation to hearing sensitivity and speech recognition ability.